Adjustable center for rotary speed indicators and the like



July 1, 1931Q B, L, METZGER 1,813,055

ADJUSTABLE CENTER FOR ROTARY SPEED INDICATORS AND THE LIKE Filed April 6, 1929 Patented July 7, 1931 UNITED STATES PATENT OFFICE BENJAMIN L. METZGER, OF TOLEDO, OHIO Application filed April 6,

This invention relates to an adjustable center particularly adapted to be used in deter mining the speed of rotation of various machine tools, where the spindle openings are of different diameters. It may also be used in determining speed of rotation of lathes, or in gaging fixtures for centering the work, or in other relations where it is desirable to effect a connection with a rotary member having a a socket or recess in its end.

The general object of the invention therefore, is to provide adjustable means whereby a single rotary member, such as a revolution speed indicator or counter of the usual type,

is may be used in connection with various spindles having openings of different diameters, or if need be, in connection with a solid spindle having a center in its end.

The specific construction of the invention,

20 in its present embodiment, will be more particularly described in connection with the accompanying drawings, in which Figure 1 is a side elevation of the invention, as used in connection with a hollow spindle, the latter being shown in section.

Figure 2 is a plan view of the invention folded.

Figure 3 is a side elevation of the invention as shown in Figure 2.

Figure 4 is a detail perspective view of a portion of the shank with the stop adjustable thereon.

The invention, which is shown. in Figure 1 as connected with a hollow spindle 5, comprises afiat shank 6 with an extension 7 welded or otherwise secured to one end thereof. The outer end of the extension 7 is formed with a split socket 8 adapted to receive the spindle 9 of a revolution speed counter 10 of the usual type. The end of the spindle 9 has a force [it in the socket 8, and the bottom of the latter is formed with converging faces to receive the correspondingly shaped end of the spindle.

5 Oppositely disposed wings 11 are pivotally connected at 12 to the opposite end of the shank 6 and are adapted to be adjusted outwardly to the proper angle to effect engagement with the socket 5, according to the di- 0 ameter of the latter. A stop 13 in the form of 1929. Serial No. 353,650.

a band is slidably mounted on the shank 6 and may be adjusted to engage one or another pair of notches 14; formed in the inner edges of the wings 11, depending upon'the spread of the wings which is necessary to engage the socket.

lVhen the adjustable center is not in use, the wings 11 may be folded as shown in Figures 2 and 3. hen the wings are folded, they are sprung outwardly and exert pressure against opposite faces of the band 13, to prevent rattling. In order to facilitate the folding of the wings, the end portion of each wing has its inner edge bevelled, as shown at 15, so that it will ride up on the band 13. This also makes it easy to engage the wings by the finger or thumb to unfold them.

The shank 6 preferably extends beyond the piv t 12 and is tapered to form a point 16 which is adapted to engage the center formed in the end of a solid spindle.

From the foregoing description, it will be seen that the invention is capable of use in connection with a rotary speed counter of the usual type, for determining the speed of a great variety of rotating members, whether hollow spindles of various diameters, or solid spindles formed with centers. Vhen the device is not in use, it may be folded and conveniently carried in one pocket.

lVhile I have shown and described speciiically only one form of the invention, it is apparent that the same may be considerably modified without departing from the scope of the appended claims.

What I claim is:

1. In a device of the character described, the combination with a. shank, of oppositely disposed wings pivoted thereto and having opposed notches in their inner edges, and a stop selectively engageable with the notches to limit the inward movement of said wings.

2. In a device of the character described. the combination with a shank, of oppositely disposed wings pivoted thereto and having opposed notches in their inner edges, and a band adjustable longitudinally of said shank to limit the inward movement of said wings.

3. In a device of the character described,

the combination with a flat shank, of oppositely disposed wings pivoted thereto and having opposed notches in their inner edges, and a band encompassing said shank and adjustable longitudinally thereof to selectively engage the notches and limit the inward movement of said wings,means for limiting the outward adjustment of said band to a position partially within the circumference described by the ends of said wings, said ends being beveled on one edge so as to ride up on the band when the wings are folded.

4. In adevice of the character described, the combination with a shank, of means for connecting said shank to a hollow spindle, said means comprising a pair of oppositely disposed wings pivotally adjustable with respect to said shank, said shank terminating beyond the pivot in a tapered end engageable with a center in the end of a solid spindle.

5. In a device of the character described, the combination with a shank, of oppositely disposed wings pivoted thereto and having opposed notches in their edges, and astop selectively engageable with the notches to limit the inward movement of said wings, said shank terminating beyond the pivot in a tapered end engageable with a center in the end of a solid spindle.

In testimony whereof I have hereunto signed my name to this specification.

BENJAMIN L. METZGER. 

